Gas liquefaction method and system

ABSTRACT

The present invention relates to a gas liquefaction system to achieve the purpose of conveniently providing cold energy to liquefy a gas. The gas liquefaction system includes a gas delivery passageway, gas driving equipment and at least two pieces of gas liquefaction equipment that are arranged according to level. The gas driving equipment is configured to drive a gas to enter the gas liquefaction system from the gas inlet end. The gas liquefaction equipment is configured to liquefy the gas in the order of the levels. The gas liquefaction system further includes gasification equipment which is configured, when any arbitrary gas liquefaction equipment of the at least two pieces of gas liquefaction equipment is in need of cold energy for gas liquefaction, to exchange heat with the liquefied gas released from the liquefied gas storage tank that contains already liquefied gas and is associated with a gas liquefaction equipment which is at a level higher than or equal to the level of the arbitrary gas liquefaction equipment, thereby gasifying the liquefied gas released from the liquefied gas storage tank. The gas liquefaction system further includes a cold energy pipeline configured to deliver the cold energy generated by gasification to the arbitrary gas liquefaction equipment, so that the arbitrary gas liquefaction equipment receives the cold energy to exchange the heat generated during gas compression. In addition, the present invention also relates to a gas liquefaction method.

TECHNICAL FIELD

The present disclosure generally relates to the technical field of gas liquefaction, in particular to a gas liquefaction method and a gas liquefaction system.

BACKGROUND

In recent years, with the development of all fields and industries, the demand for liquefied gases has been growing increasingly, and the liquefied gas industry has witnessed prosperous development.

At present, gases are generally liquefied by specialized gas liquefaction equipment. To liquefy a gas, the gas is compressed, and during compression the gas liquefaction equipment exchanges heat generated by continuously adding external cold energy.

As it is required to keep adding external cold energy for the gas liquefaction equipment to cool the gases during the heat exchange, and therefore how to provide sufficient cold energy remains an issue.

SUMMARY

Accordingly, the present invention mainly aims to provide a gas liquefaction method and a gas liquefaction system to achieve a purpose of providing sufficient cold energy more quickly and conveniently to liquefy the gases.

A first aspect of the embodiments of the present invention provides a gas liquefaction system, including a gas delivery passageway, gas driving equipment and at least two pieces of gas liquefaction equipment that are arranged at different levels, wherein the gas driving equipment is disposed at a gas inlet end of the gas delivery passageway, the gas delivery passageway is communicated with gas inlet ends of the at least two pieces of gas liquefaction equipment, and each of the at least two pieces of gas liquefaction equipment is equipped with a liquefied gas storage tank respectively. The gas driving equipment is configured to drive a gas to enter the gas liquefaction system from the gas inlet end of the gas delivery passageway, the at least two pieces of gas liquefaction equipment that are arranged at different levels are configured to liquefy the gas that enters the gas liquefaction system from a gas inlet end of the gas liquefaction equipment in an order based on the levels, and the liquefied gas that is obtained by means of a liquefaction reaction enters the corresponding liquefied gas storage tanks. The gas liquefaction system further includes gasification equipment. When any arbitrary gas liquefaction equipment of the at least two pieces of gas liquefaction equipment is in need of cold energy for gas liquefaction, the gasification equipment can be used to exchange heat with the liquefied gas released from the liquefied gas storage tank that contains already liquefied gas and associated with a gas liquefaction equipment which is at a level higher than or equal to the level of the arbitrary gas liquefaction equipment, thereby gasifying of the liquefied gas released from the liquefied gas storage tank. The gas liquefaction system further includes a cold energy pipeline configured to deliver the cold energy generated by the gasification reaction to the arbitrary gas liquefaction equipment, so that the arbitrary gas liquefaction equipment receives the cold energy to exchange the heat generated during gas compression. Through the heat exchange, the gas in the arbitrary gas liquefaction equipment reaches or drops below a critical liquefaction temperature of the gas, so that the gas is liquefied, and then the liquefied gas obtained by the liquefaction reaction enters the liquefied gas storage tank associated with the arbitrary gas liquefaction equipment.

A second aspect of the embodiments of the present invention provides a gas liquefaction method, which is applicable to a gas liquefaction system including a gas delivery passageway, gas driving equipment and at least two pieces of gas liquefaction equipment that are arranged at different levels. The gas liquefaction method includes the following steps: arranging the gas driving equipment at a gas inlet end of the gas delivery passageway, communicating the gas delivery passageway with gas inlet ends of the at least two pieces of gas liquefaction equipment, providing a liquefied gas storage tank for each of the at least two pieces of gas liquefaction equipment respectively; using the gas driving equipment to drive a gas to enter the gas liquefaction system from the gas inlet end of the gas delivery passageway; using the at least two pieces of gas liquefaction equipment to liquefy the gas that enters the gas liquefaction system from a gas inlet end of the gas liquefaction equipment in an order of the levels, wherein the liquefied gas obtained by liquefaction enters a designated liquefied gas storage tank for the gas liquefaction equipment; when any gas liquefaction equipment of the at least two pieces of gas liquefaction equipment is in need of cold energy for gas liquefaction, using the gasification equipment to exchange heat with the liquefied gas released from the liquefied gas storage tank that contains already liquefied gas is associated with any gas liquefaction equipment which is at a level higher than or equal to the level of the gas liquefaction equipment in need of cold energy, thereby gasifying the liquefied gas released from the liquefied gas storage tank; and delivering the cold energy generated by the gasification reaction to the arbitrary gas liquefaction equipment through the cold energy pipeline, so that the arbitrary gas liquefaction equipment receives the cold energy to exchange heat that is generated during a gas compression. Through the heat exchange, the gas in the arbitrary gas liquefaction equipment reaches or drops below its critical liquefaction temperature, so that the gas is liquefied and then enters the liquefied gas storage tank associated with the arbitrary gas liquefaction equipment.

The present disclosure has the following beneficial effects:

According to embodiments of the present disclosure, the gas liquefaction system of the present invention includes a gas delivery passageway, a gas driving equipment and at least two pieces of gas liquefaction equipment arranged at different levels; the gas entering the gas liquefaction system from the gas inlet end of the gas liquefaction equipment is liquefied based on the levels; the liquefied gas obtained by liquefaction enters a liquefied gas storage tank provided for the gas liquefaction equipment. When any arbitrary gas liquefaction equipment of the at least two pieces of gas liquefaction equipment is in need of cold energy for gas liquefaction, the gasification equipment can be used to exchange heat with the liquefied gas released from the liquefied gas storage tank that contains already liquefied gas and is associated with any gas liquefaction equipment which is at a level higher than or equal to the level of the arbitrary gas liquefaction equipment, thereby gasifying the liquefied gas released from the liquefied gas storage tank. The cold energy generated by the gasification reaction is delivered to the arbitrary gas liquefaction equipment through the cold energy pipeline, so that the arbitrary gas liquefaction equipment receives the cold energy to exchange heat that is generated during a gas compression, resulting in the liquefaction of the gas. As can be seen, the liquefied gas that is obtained from the gas liquefaction equipment at an higher level by liquefaction can provide sufficient cold energy for the heat exchange in the gas liquefaction in the gas liquefaction equipment at a lower level, and therefore, the cold energy provided by the liquefied gas obtained by liquefaction at a certain higher level can be used to liquefy the gas at its next lower level in a convenient and energy-saving manner without having to continuously provide additional cold energy sources, so as to achieve a chain effect. The gas liquefaction system may be used in for the liquefaction of the gas in a larger area and in higher efficiency as well as the continuous production of the liquefied gas.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solution of the embodiments of the present disclosure or in the prior art, the drawings, which are referenced in the description in the embodiments or in the prior art, will be briefly described below. It is obvious that the drawings described herein are only related to some embodiments of the present disclosure. Based on the described drawings herein, a person skilled in the art can obtain other drawings without any inventive work.

FIG. 1-1 is a first structural schematic diagram of a gas liquefaction system according to an embodiment of the present invention;

FIG. 1-2 is a second structural schematic diagram of a gas liquefaction system according to an embodiment of the present invention;

FIG. 2 is a third structural schematic diagram of a gas liquefaction system according to an embodiment of the present invention;

FIG. 3 is a fourth structural schematic diagram of a gas liquefaction system according to an embodiment of the present invention;

FIG. 4 is a fifth structural schematic diagram of a gas liquefaction system according to an embodiment of the present invention;

FIG. 5 is a schematic flow chart of a gas liquefaction method according to an embodiment of the present invention.

DESCRIPTION OF THE EMBODIMENTS

In order to achieve the purpose of providing sufficient cold energy for the gas liquefaction quickly and conveniently, level-by-level liquefaction is employed according to the embodiments of the present invention; namely, according to the embodiments of the present disclosure, a gas liquefaction system includes at least two pieces of gas liquefaction equipment that are arranged at different levels. The plurality of gas liquefaction equipment is employed one by one to liquefy the gas that enters the gas liquefaction system from a gas inlet end of the gas liquefaction equipment in an order based on the levels. When any arbitrary gas liquefaction equipment of the at least two pieces of gas liquefaction equipment is in need of cold energy for gas liquefaction, the gasification equipment can be used to exchange heat with the liquefied gas released from the liquefied gas storage tank associated with any gas liquefaction equipment which is at a level higher than or equal to the level of the arbitrary gas liquefaction equipment, thereby gasifying the liquefied gas released from the liquefied gas storage tank, and deliver the cold energy generated by the gasification to the arbitrary gas liquefaction equipment (it should be noted that a person ordinarily skilled in the art is familiar with the techniques of collecting and delivering the cold energy, which will not be specifically described herein below), so that the arbitrary gas liquefaction equipment receives the cold energy to exchange the heat generated during gas compression. Through the heat exchange, the gas in the arbitrary gas liquefaction equipment reaches or drops below its critical liquefaction temperature, so that the gas is liquefied. The liquefied gas that is obtained from the gas liquefaction equipment at an higher level by liquefaction can provide sufficient cold energy for the heat exchange in the gas liquefaction in the gas liquefaction equipment at a lower level, and therefore, the cold energy provided by the liquefied gas obtained by liquefaction at higher levels can be used to liquefy the gas at next lower levels in a convenient and energy-saving manner without having to continuously provide additional cold energy sources.

In order to make the objects, features and advantages of the embodiments of the present disclosure more apparent and understandable, the embodiments of the present invention will be further described in detail in connection with the accompanying drawings and embodiments of the present disclosure.

First Embodiment

Firstly, with reference to FIG. 1-1, which illustrates a first structural schematic diagram of a gas liquefaction system according to an embodiment of the present invention.

As illustrated in FIG. 1-1, the gas liquefaction system includes a gas delivery passageway 101, gas driving equipment 102 and at least two pieces of gas liquefaction equipment 103, 104 and 105 that are arranged at different levels, wherein the gas driving equipment 102 is arranged at a gas inlet end of the gas delivery passageway 101; the gas delivery passageway 101 is communicated with gas inlet ends of the at least two pieces of gas liquefaction equipment, such as the gas liquefaction equipment 103, the gas liquefaction equipment 104 and the gas liquefaction equipment 105; each of the at least two pieces of gas liquefaction equipment is provided with a liquefied gas storage tank, respectively; for example, a gas outlet end of the gas liquefaction equipment is communicated with the gas inlet end of the liquefied gas storage tank.

The gas driving equipment 102 can be configured to drive a gas to enter the gas liquefaction system from the gas inlet end of the gas delivery passageway 101;

The at least two pieces of gas liquefaction equipment 103, 104 and 105 that are arranged at different levels can be configured to liquefy the gas that enters the gas liquefaction system from a gas inlet end of the gas liquefaction equipment in an order according to the levels, wherein the liquefied gas obtained by liquefaction enters the corresponding liquefied gas storage tanks. For example, an order of levels of the gas liquefaction equipment as illustrated in FIG. 1-1 may be the gas liquefaction equipment 103, the gas liquefaction equipment 104 and the gas liquefaction equipment 105 from front to back.

Moreover, according to the embodiment of the present invention, the gas liquefaction system may further include:

gasification equipment 106, which is configured to exchange heat with the liquefied gas released from the liquefied gas storage tank associated with a gas liquefaction equipment which is at a level higher than or equal to the level of the arbitrary gas liquefaction equipment, thereby gasifying the liquefied gas released from the liquefied gas storage tank; and

a cold energy pipeline 107, which is configured to deliver the cold energy generated by the gasification to the arbitrary gas liquefaction equipment, so that the gas liquefaction equipment receives the cold energy to exchange heat generated during gas compression. Through the heat exchange, the gas in the gas liquefaction equipment reaches or drops below its critical liquefaction temperature, so that the gas is liquefied, and the liquefied gas then enters the liquefied gas storage tank associated with the arbitrary gas liquefaction equipment.

For example, the liquefied gas storage tank 103 a may be communicated with the gas inlet end of the cold energy pipeline 107, and the cold energy pipeline 107 delivers the cold energy to the outside of an air cylinder of the arbitrary gas liquefaction equipment to quickly cool the gas in the arbitrary gas liquefaction equipment. It can be understood that if the this does not reach the critical temperature for the liquefaction, other cooling media, e.g., dry ice, may be added to realize auxiliary cooling. In addition, when the liquefied gas is in sufficient amount, the power that is released by gasification may also be used to drive a generator to generate electricity while the cold energy is released; and the generated electricity may be used to provide power for any equipment, such as a gas liquefaction system, and a power grid.

It should be noted that the gas liquefaction equipment described herein may be general gas liquefaction equipment, and is not limited to any specific structure. For example, the gas liquefaction equipment may be separately provided with their own respective air cylinders, may share a common gas compressor, and may also be separately provided with separate gas compressors. When the gas liquefaction equipment liquefies the gas, the gas can be cooled, pressurized and liquefied according to their physical properties such as the liquefaction temperature, liquefaction pressure and the like of the gas that enters the air cylinder. For the first gas liquefaction equipment to liquefy the gas in terms of the order of the levels, some dry ice may be added into the gas liquefaction equipment at an appropriate time to start the cooling process, and a pressure is applied in the gas liquefaction equipment when the temperature reaches the critical temperature for the liquefaction. For example, if in a level-by-level scheme of liquefaction the gas that is liquefied by the first gas liquefaction equipment is a carbon dioxide gas, the pressure can be applied in the gas liquefaction equipment when the temperature reaches or drops below the critical temperature of 31 degrees centigrade for the liquefaction, and the liquefied carbon dioxide enters the liquefied gas storage tank (part of the liquefied carbon dioxide may form dry ice).

As seen above, according to the gas liquefaction system disclosed by the present embodiment, the liquefied gas that is obtained from the gas liquefaction equipment at an higher level by liquefaction can provide sufficient cold energy for the heat exchange during the gas liquefaction in the gas liquefaction equipment at a lower level, and therefore, the cold energy provided by the liquefied gas obtained by liquefaction at higher levels can be used to liquefy the gas at next lower levels in a convenient and energy-saving manner without having to continuously provide additional cold energy sources

According to the embodiment of the present disclosure, the liquefied gas storage tank in the gas liquefaction system may be a sealed high-pressure container; a safety valve may be arranged at each of gas inlets and gas outlets of the respective equipment; the operating status and related data of each equipment may be collected to a central control station, and the central control station controls each equipment of the gas liquefaction system of this embodiment to liquefy the gas. Moreover, in order to ensure the operating safety of the gas liquefaction system, alarm and automatic depressurization equipment may be provided at certain positions of the gas liquefaction system.

It can be understood that the cold energy that is generated by means of the gasification reaction may also be temporarily stored in a cold energy storage tank before being delivered to the gas liquefaction equipment through the cold energy pipeline 107, and the cold energy is then delivered to the arbitrary gas liquefaction equipment for the liquefaction reaction of the gas in the arbitrary gas liquefaction equipment.

In addition, as illustrated in FIG. 1-2, the gas liquefaction system according to the present embodiment may also include heat insulating pipelines (such as the heat insulating pipeline 103 c, the heat insulating pipeline 104 c and the heat insulating pipeline 105 c as illustrated in FIG. 1-2) that are communicated with the gas liquefaction equipment, wherein the heat insulating pipelines are configured to collect heat energy that is generated during the liquefaction and deliver the heat energy to heat energy storage tanks (such as the heat energy storage tank 103 d, the heat energy storage tank 104 d and the heat energy storage tank 105 d as illustrated in FIG. 1-2) for storage, to provide the heat energy when the gasification equipment performs heat exchange on the liquefied gas. For example, during the process that the gas in the arbitrary gas liquefaction equipment is liquefied, the heat energy that is generated during the liquefaction may be collected to a heat energy storage tank that can insulate heat through the heat insulating pipeline; as illustrated in FIG. 1-2, the gas liquefaction equipment 103 may collect the heat energy that is generated during the liquefaction to the heat energy storage tank 103 d that can insulate heat through the heat insulating pipeline 103 c, the gas liquefaction equipment 104 may collect the heat energy that is generated during the liquefaction to the heat energy storage tank 104 d that can insulate heat through the heat insulating pipeline 104 c, and the gas liquefaction equipment 105 may collect the heat energy that is generated during the liquefaction to the heat energy storage tank 105 d that can insulate heat through the heat insulating pipeline 105 c, so that required heat energy can be provided for the heat exchange when the gasification equipment 106 performs the heat exchange on the liquefied gas to gasify the liquefied gas. For example, the heat energy in the heat energy storage tanks may be delivered into the gasification equipment by a medium such as water, air and the like through the heat insulating pipelines, to reduce or avoid the additional provision of heat energy. During the gasification process of the liquefied gas in the liquefied gas storage tank, all cold energy that is generated during the gasification may also be collected to the cold energy storage tanks that insulate heat. It should be noted that a person ordinarily skilled in the art is familiar with the techniques for collecting and delivering cold energy and heat energy, which will not be specifically described in the present disclosure. Through the collection of the cold energy and the heat energy, the heat energy that is generated during the liquefaction and the cold energy that is generated during the gasification can each play a role in the gas liquefaction system; the cold energy and the heat energy can be neutralized at a certain stage of the liquefaction and the gasification, to increase the efficiency.

Second Embodiment

According to an embodiment of the present invention, a gas liquefaction system can be applied to a wind field to solve the bottleneck problem on grid-connected wind power system. Specifically, reference is made to FIG. 2 that illustrates a third structural schematic diagram of a gas liquefaction system.

As illustrated in FIG. 2, as for the liquefied gas storage tanks of the at least two pieces of gas liquefaction equipment, a gas outlet end of at least one liquefied gas storage tank is communicated with gasification equipment 106 (for example, gas outlet ends of the liquefied gas storage tanks, such as the gas outlet ends of a liquefied gas storage tank 103 a, a liquefied gas storage tank 104 a and a liquefied gas storage tank 105 a, of the at least two gas liquefaction equipment are all communicated with the gasification equipment, or the gas outlet ends of the liquefied gas storage tanks, such as the liquefied gas storage tank 104 a and the liquefied gas storage tank 105 a as illustrated in FIG. 2, of the gas liquefaction equipment that is not arranged at the foremost in terms of the levels are communicated with the gasification equipment). When a wind turbine in the wind field cannot supply sufficient electricity to a power grid 100, the gasification equipment 106 may be used to gasify the liquefied gas in any liquefied gas storage tank that is communicated with the gasification equipment, and may further include an electric generator 111. The electric generator 111 is configured to be driven by the gas that is released from the gasification equipment 106 to supply electricity to the power grid 100. For example, gas driving equipment 102 may be specifically used to drive the gas to enter the gas liquefaction system from a gas inlet end of a gas delivery passageway when the wind in the wind field exceeds a certain threshold speed.

Accordingly, with respect to the bottleneck problem on grid connection caused by the instability of the wind energy or a failure of the wind turbine itself or the like, according to the present embodiment, an appropriate operation area for liquefying air can be selected in the wind field, and the gas liquefaction system according to the present embodiment can be applied in the operation area to utilize excessive wind energy to liquefy air, and when the wind is of insufficient speed or stops, or if some or all of the wind turbines have failed, gasify the liquefied gas to release power to drive the electric generator to generate electricity so as to supply the electricity to the power grid. Therefore, the power supply of the power grid is extended, and the impact on the power grid due to large or fast fluctuation in the wind energy is reduced.

It should be noted that according to the embodiment of the present disclosure, a power source of the gas liquefaction system may be electric power that is generated by the wind turbines in the wind field. For example, the electric power can be provided for the gas driving equipment 102, gas liquefaction equipment 103, 104, 105 and the like; the power source of the gas liquefaction system may also be electric power that is generated by other energy sources, such as excessive electric energy at mountain peaks or valleys, oceanic tidal energy, geothermal energy and solar energy and the like.

For example, the electric power that is generated by wind turbines in the wind field supplies an electric power source to the gas liquefaction system, which may be implemented in the following two manners: in the first, the wind turbines in the wind field generates electricity based on a predetermined power level, wherein the predetermined power level may be set according to the requirement of the power grid; when the wind energy is large and exceeds the predetermined power level, the wind energy which exceeds the predetermined power level may be centralized in the operation area and converted into the electric power as the electric power source of the gas liquefaction system; in the second, certain of the wind turbines may be selected in the wind field; when the wind energy is large, the selected wind turbines are used to provide the electric power source for the gas liquefaction system to liquefy air. Either of the above manners is acceptable. Furthermore, when the wind energy in the wind field is not continuous, intermittent wind energy may also be converted into electric energy and stored in a storage battery to supply the electric power source to the gas liquefaction system to start air liquefaction when the electric power in the storage battery is enough to start the gas liquefaction system.

It should be noted that according to the embodiment of the present disclosure, the gasification equipment 106 may include one or more gasification equipment; for example, the gas outlet end of the liquefied gas storage tank of each gas liquefaction equipment may be communicated with one gasification equipment; for another example, the gas outlet of the liquefied gas storage tank of each gas liquefaction equipment may be communicated with a respective corresponding gasification equipment separately. The specific implementation is not limited in the present disclosure. According to the present embodiment, the gasification equipment may include necessary equipment such as a heat exchanger and the like.

When the wind turbines cannot supply sufficient electricity to the power grid, the decision as to which of the liquefied gas storage tanks is to be selected and how much liquefied gas to be released from the selected liquefied gas storage tank can be based on the requirements for stabilizing the power grid and extending the power generation under the actual circumstances, which is not limited in the present disclosure. Moreover, the released gas may also be delivered to the power grid together with the wind power of other wind turbines at the same time of driving the electric generator to supply power to the power grid, so as to eliminate the impact on the power grid due to the variation in the wind power of the wind turbines. For example, when the forecast indicates no wind, the gas in the liquefied gas storage tanks may be released to drive a motor to supply electricity to the power grid, so that the power grid can obtain the electric power source in time to ensure safe disconnection of the wind turbines from the grid before the wind turbines cannot supply power and disconnected from the grid, thereby minimizing the impact on the power grid. When the forecast indicates that the wind speed is high and the wind energy will exceed the predetermined power level, the gas driving equipment is started to drive the air to enter the gas delivery passageway to start the air liquefaction, and the excessive wind energy is converted into the liquefied gas for storage.

It should be noted that the embodiment may also combine the embodiments as illustrated in FIG. 1-2; the respective gas liquefaction equipment is communicated with heat insulating pipelines to store heat energy that is generated during the liquefaction in heat energy storage tanks, so as to provide the heat energy for the gasification equipment during the gas gasification.

Third Embodiment

In combination with any of the above embodiments, when the gas is a gas mixture, such as natural air in a wind field, a gas liquefaction system according to the embodiment of the present disclosure can separate several pure gases from the gas mixture and liquefy the pure gases separately. Reference is made to FIG. 3 which is a fourth structural schematic diagram of a gas liquefaction system according to an embodiment of the present disclosure where a specific implementation mode is illustrated.

As illustrated in FIG. 3, the gas liquefaction system according to the present embodiment may further include filtration equipment that is arranged for each gas liquefaction equipment respectively and used to separate the pure gases.

In the embodiment, in an order of the levels from front to back, and starting from a gas inlet of a gas delivery passageway, at least two pieces of gas liquefaction equipment are communicated with the gas delivery passageway through the filtration equipment that is arranged for the gas liquefaction equipment one by one, wherein the gas inlet end of each gas liquefaction equipment is communicated with a separating opening of each filtration equipment that is arranged for the gas liquefaction equipment, and gas inlets of the respective filtration equipment are communicated with the gas delivery passageway (for example, in the order of the levels from front to back, and starting from the gas inlet of the gas delivery passageway 101, the gas liquefaction equipment 103 is communicated with the gas delivery passageway through the filtration equipment 103 b, the gas liquefaction equipment 104 is communicated with the gas delivery passageway through the filtration equipment 104 b, and the gas liquefaction equipment 105 is communicated with the gas delivery passageway through the filtration equipment 105 b);

As for the first gas liquefaction equipment that is communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway, the gas inlet of the filtration equipment of the first gas liquefaction equipment is communicated with the gas inlet end of the gas delivery passageway. As for any arbitrary gas liquefaction equipment except for the first gas liquefaction equipment, the gas inlet of the filtration equipment of the arbitrary gas liquefaction equipment is communicated with a gas outlet of the filtration equipment of the previous gas liquefaction equipment that is arranged before the arbitrary gas liquefaction equipment through the gas delivery passageway (for example, the gas inlet of the filtration equipment 103 b of the first gas liquefaction equipment 103 is communicated with the gas inlet end of the gas delivery passageway 101, the gas inlet of the filtration equipment 104 b of the gas liquefaction equipment 104 is communicated with gas outlet of the filtration equipment 103 b through the gas delivery passageway 101, and the gas inlet of the filtration equipment 105 b of the gas liquefaction equipment 105 is communicated with the gas outlet of the filtration equipment 104 b through the gas delivery passageway 101);

The filtration equipment, such as the filtration equipment 103 b, 104 b, 105 b, is configured to filter the gas that enters the gas liquefaction system from the gas inlets of the filtration equipment. The separated pure gases enter the gas liquefaction equipment from separating openings, and the remaining gases are discharged out of the gas outlets.

In addition, in order to ensure pure gases to enter the gas liquefaction equipment, air filtration equipment may also be arranged at an inlet such as a ventilator and the like of gas driving equipment to filter small particulate impurities such as sand, dust and the like.

For example, the gas may be the natural air in the wind field; as illustrated in FIG. 3, the at least two pieces of gas liquefaction equipment may include carbon dioxide liquefaction equipment 103 that is configured to liquefy carbon dioxide, oxygen liquefaction equipment 104 that is configured to liquefy oxygen and nitrogen liquefaction equipment 105 that is configured to liquefy nitrogen, wherein the carbon dioxide liquefaction equipment 103 is the first gas liquefaction equipment that is communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway, the oxygen liquefaction equipment 104 is the second gas liquefaction equipment that is communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway, and the nitrogen liquefaction equipment 105 is the third gas liquefaction equipment that is communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway.

Of course, it should be noted that the embodiment of the present disclosure is not limited to such implementation mode, and the respective gas liquefaction equipment may be used to accommodate and liquefy any of the pure gases, which is not limited in the present disclosure.

In such implementation mode, for example, a filtration membrane suitable to separate the carbon dioxide may be included in the filtration equipment 103 b arranged at the gas inlet end of the carbon dioxide liquefaction equipment; a filtration membrane suitable to separate oxygen may be included in the filtration equipment 104 b which is arranged at the gas inlet end of the oxygen liquefaction equipment; and a filtration membrane suitable to separate nitrogen may be included in the filtration equipment 105 b which is arranged at the gas inlet end of the nitrogen liquefaction equipment.

For example, in terms of the order of levels, the carbon dioxide liquefaction equipment may be arranged in front of the oxygen liquefaction equipment and the nitrogen liquefaction equipment, and the oxygen liquefaction equipment may be arranged at the same level as, or a different level than that of the nitrogen liquefaction equipment; for example, the oxygen liquefaction equipment is disposed in front of the nitrogen liquefaction equipment to liquefy the oxygen, which is easier to liquefy than nitrogen, before liquefying nitrogen, wherein gasification equipment 106 may be configured to perform heat exchange on liquefied carbon dioxide released from liquefied gas storage tank 103 a which is configured for the carbon dioxide liquefaction equipment 103 to gasify of the liquefied carbon dioxide when cold energy is required for the liquefaction reaction of the gas in the oxygen liquefaction equipment 104.

The cold energy pipeline 107 may be configured to deliver the cold energy that is generated during the gasification of the liquefied carbon dioxide to the oxygen liquefaction equipment 104, so that the oxygen liquefaction equipment 104 receives the cold energy to exchange heat that is generated during oxygen compression. The oxygen in the oxygen liquefaction equipment can reach or drop below a critical temperature for the liquefaction of the oxygen more quickly through the heat exchange. As a result, the oxygen is liquefied. The liquid oxygen obtained from the liquefaction reaction enters liquefied gas storage tank 104 a configured for the oxygen liquefaction equipment 104.

When the cold energy generated during the gasification of the liquefied carbon dioxide released from the liquefied gas storage tank 103 a of the carbon dioxide liquefaction equipment 103 is insufficient, the gasification equipment 106 may also be used to perform the heat exchange on a portion of liquefied oxygen released from the liquefied gas storage tank 104 a to gasify the liquefied oxygen;

The cold energy pipeline 107 may also be used to deliver the cold energy generated during the gasification of the liquefied oxygen to the oxygen liquefaction equipment 104 and/or the nitrogen liquefaction equipment 105, so that the oxygen liquefaction equipment 104 and/or the nitrogen liquefaction equipment 105 receive the cold energy to exchange heat generated during gas compression. The gas in the oxygen liquefaction equipment and/or the nitrogen liquefaction equipment can reach or drop below a critical temperature for the liquefaction of the gas more quickly through the heat exchange, and therefore the gas in the oxygen liquefaction equipment and/or the nitrogen liquefaction equipment is liquefied.

The entire process of liquefying the carbon dioxide, the oxygen and the nitrogen according to the gas liquefaction system according to the present embodiment will be described in detail herein below in combination of the above embodiments. For example:

Wind power-based electric power that is centralized in an operation area can be supplied to the gas driving equipment 102 and the gas liquefaction equipment 103, 104, 105;

The gas driving equipment 102 drives air to enter the gas liquefaction system from the gas inlet end of the gas delivery passageway. After the air is filtered by the filtration equipment 103 b, the separated carbon dioxide gas enters the carbon dioxide liquefaction equipment 103 from the separating opening of the filtration equipment 103 b. When the carbon dioxide in the carbon dioxide liquefaction equipment reaches a certain concentration, the carbon dioxide liquefaction equipment 103 pressurizes the gas in the carbon dioxide liquefaction equipment 103. Dry ice may be added during the pressurization process to start the cooling process. When the gas in the carbon dioxide liquefaction equipment reaches or drops below the critical temperature for the liquefaction of the carbon dioxide, the pressurization is continued, and the carbon dioxide is liquefied. The liquefied carbon dioxide enters the liquefied gas storage tank 103 a that is communicated with the carbon dioxide liquefaction equipment 103.

Wherein, during the liquefaction of carbon dioxide, if there is remaining wind power-based electric power in the centralized operation area, the remaining wind power-based electric power as an electric power source may be continued to be supplied to the gas driving equipment and the gas liquefaction equipment. If there is no remaining wind power-based electric power in the centralized operation area, a spare storage battery may also be employed as an electric power source of a power supply device to continue to supply power to the gas driving equipment and the gas liquefaction equipment.

The remaining gas discharged out of the gas outlet of the filtration equipment 103 b enters the gas inlet of the filtration equipment 104 b for filtration, and the separated oxygen gas enters the oxygen liquefaction equipment 104 from the separating opening of the filtration equipment 104 b. When the oxygen in the oxygen liquefaction equipment 104 reaches a certain concentration and after the liquefied gas storage tank 103 a collects the liquefied carbon dioxide of a certain concentration, heat exchange is carried out on the liquefied carbon dioxide that is released from the liquefied gas storage tank 103 a of the carbon dioxide liquefaction equipment 103 to gasify the released liquefied carbon dioxide. The cold energy is delivered to the oxygen liquefaction equipment 104 through the cold energy pipeline 107, so that the oxygen liquefaction equipment 104 receives the cold energy to exchange heat that is generated during the gas compression. Through the heat exchange, the oxygen in the oxygen liquefaction equipment reaches or drops below the critical temperature for the liquefaction of the oxygen, and the oxygen is liquefied. The liquefied oxygen (which may also include an amount of solid oxygen) that is obtained through the liquefaction reaction enters the liquefied gas storage tank 104 b.

Wherein, if the liquefied carbon dioxide is insufficient, the gasification equipment 106 may also be utilized to gasify an amount of liquefied oxygen in the liquefied gas storage tank 104 b. The cold energy is delivered to the oxygen liquefaction equipment 104 through the cold energy pipeline 107.

The remaining gas that is discharged out of the gas outlet of the filtration equipment 104 b enters the gas inlet of the filtration equipment 105 b for filtration, and the separated nitrogen gas enters the nitrogen liquefaction equipment 105 from the separating opening of the filtration equipment 105 b. When the nitrogen in the nitrogen liquefaction equipment 105 reaches a certain concentration and a certain amount of liquefied gas is available in the liquefied gas storage tank 103 a or the liquefied gas storage tank 104 a, the gas in the nitrogen liquefaction equipment 105 is liquefied, and heat exchange is carried out on the liquefied gas that is released from the liquefied gas storage tank 103 a or the liquefied gas storage tank 104 a to gasify the released liquefied gas. The cold energy is delivered to the nitrogen liquefaction equipment 105 through the cold energy pipeline 107, so that the nitrogen liquefaction equipment 105 receives the cold energy to exchange heat that is generated during the gas compression. Through the heat exchange, the nitrogen in the nitrogen liquefaction equipment reaches or drops below the critical temperature more quickly, and the nitrogen is liquefied. The liquefied nitrogen (which may include an amount of solid nitrogen) obtained through the liquefaction reaction enters the liquefied gas storage tank 105 a.

It should be noted that when the liquefied carbon dioxide or the liquefied oxygen is gasified, if the liquefied gas is sufficient, an electric generator 111 may also be driven by the gas released from the gasification equipment 106 to supply electricity to the gas driving equipment 102 and/or the gas liquefaction equipment 103, 104, 105. It should be noted that the electric generator 111 may also provide electric power for any equipment in the gas liquefaction system according to the embodiment of the present disclosure, or supply electricity to a power grid at the same time, which is not limited in the present disclosure.

Of course, the present embodiment is not limited to an arrangement of three pieces of gas liquefaction equipment only, and more gas liquefaction equipment may be included. Nor is it limited to the liquefaction of carbon dioxide, nitrogen and oxygen. For example, ammonia gas and the like may also be liquefied. The liquefied gas that is generated during the liquefaction may be pure liquefied gas or a mixture of liquefied gases, which is not limited in the present disclosure.

For example, according to the embodiment, part of liquefied oxygen in the liquefied gas storage tank may be released, and/or part of liquefied nitrogen in the liquefied gas storage tank may be released and gasified. The gasification equipment is utilized to gasify the released liquefied oxygen and/or the liquefied nitrogen. The energy that is released during the gasification reaction is utilized to drive the electric generator to generate electricity. The generated electricity may also be utilized in turn to supply electricity to the gas liquefaction system according to the present embodiment, which allows the gas liquefaction system to continue to liquefy gases, so as to produce industrial products such as liquefied oxygen, liquefied nitrogen and the like continuously in cycles. Of course, the whole process may involve manual control and management, which is not limited in the present disclosure.

It should be noted that the embodiment may also combine the embodiments as illustrated in connection with FIG. 1-2, the respective gas liquefaction equipment is communicated with heat insulating pipelines. The heat energy that is generated during the liquefaction is stored in heat energy storage tanks, and the heat energy is provided to gasify the gas in the gasification equipment.

Fourth Embodiment

In combination with any of the above embodiments, after liquefied gas is gasified to generate electricity and forms high-pressure gas, a part of the gas may be discharged in the surrounding space, and the remaining gas may be recycled by gas recycling equipment such as a suction ventilator and the like, delivered back to gas liquefaction equipment through a gas recycling pipeline associated with the gas recycling equipment, and liquefied again to form the liquefied gas. For example, reference is made to FIG. 4 which illustrates a fifth structural schematic diagram of a gas liquefaction system according to an embodiment of the present disclosure for where a specific implementation mode is illustrated.

As illustrated in FIG. 4, a gas outlet end of gasification equipment 106 may also be communicated with a gas inlet end of the gas recycling equipment 109, the gas recycling equipment 109 is used to recycle the gas that is discharged out of the gasification equipment 106, the recycled gas is delivered to gas inlet end(s) of one or more gas liquefaction equipment in the at least two pieces gas liquefaction equipment through the gas recycling pipeline 110, so that the discharged gas returns to the gas liquefaction equipment again as much as possible for liquefaction.

For example, if each piece of gas liquefaction equipment is used to accommodate and liquefy a different pure gas, each liquefied gas storage tank may be accordingly communicated with one piece of gasification equipment. Correspondingly, the gas outlet end of each gasification equipment may be communicated with an independent gas recycling equipment, the gas outlet end of the gas recycling pipeline that is matched with the independent gas recycling equipment may be directly communicated with the corresponding gas liquefaction equipment that is used to accommodate and liquefy the same gas, so that the discharged pure gas may return to the gas liquefaction equipment for liquefaction, and therefore wear and tear on the filtration equipment is reduced, wherein the gas recycling equipment, for example, may include necessary devices such as a vacuum air pump and the like, the gas recycling of the gas recycling pipeline may be automatically controlled by related control equipment that is configured to control related components such as a valve of the gas recycling pipeline and the like, which will not be repeatedly described in detail in the present disclosure.

A person skilled in the art would understand that the liquefied gas storage tanks may be closed containers that can be detached. The liquefied gas storage tanks in which the liquefied gas is stored may be sold as individual products. A storage warehouse provided with safety equipment may also be provided to store the liquefied gas storage tanks. Dimensions of the air cylinder(s) of the gas liquefaction equipment can be determined according to practical requirements and are not limited in the present disclosure. The dimensions, number and materials of the liquefied gas storage tanks used to store the liquefied gas may be determined according to practical requirements. For example, the liquefied gas storage tanks may be steel storage tanks or concrete grouted storage tanks, and may be placed on the ground, underground, semi-underground or the like, and are not limited in the present disclosure. In addition, the energy that is released when the gasification equipment 106 gasifies the liquefied gas may also be provided as a power source for other equipment, for example, as the power source to drive an excavation equipment to excavate coal mines or as the power source to drive transportation vehicles and the like.

It should be noted that the embodiment may also be in combination with the embodiment as illustrated in FIG. 1-2, the respective gas liquefaction equipment is communicated with heat insulating pipelines, heat energy that is generated during the liquefaction is stored in heat energy storage tanks, and the heat energy is provided to gasify the gas in the gasification equipment.

Fifth Embodiment

Corresponding to the above gas liquefaction system, this embodiment provides a gas liquefaction method. The gas liquefaction method may be applied to the gas liquefaction system that includes a gas delivery passageway, gas driving equipment and at least two pieces of gas liquefaction equipment that are arranged at different levels. For example, with reference to FIG. 5 which illustrates a schematic diagram of a flow of the gas liquefaction method according to the embodiment, the gas liquefaction method as illustrated in FIG. 5 may include the following steps:

Step S510: arranging the gas driving equipment at a gas inlet end of the gas delivery passageway, communicating the gas delivery passageway with gas inlet ends of the at least two pieces of gas liquefaction equipment, and providing a liquefied gas storage tank for each of the at least two pieces of gas liquefaction equipment respectively;

Step S520: using the gas driving equipment to drive a gas to enter the gas liquefaction system from the gas inlet end of the gas delivery passageway;

Step S530: using the at least two pieces of gas liquefaction equipment that are arranged at different levels to liquefy the gas that enters the gas liquefaction system from a gas inlet end of the gas liquefaction equipment in an order of the levels, wherein the liquefied gas that is obtained by liquefaction enters a designated liquefied gas storage tank configured for the gas liquefaction equipment;

Step S540: when any arbitrary gas liquefaction equipment of the at least two pieces of gas liquefaction equipment is in need of cold energy for gas liquefaction, the gasification equipment can be used to exchange heat with the liquefied gas released from the liquefied gas storage tank that contains already liquefied gas and is associated with any gas liquefaction equipment which is at a level higher than or equal to the level of the gas liquefaction equipment in need of cold energy, thereby gasifying the liquefied gas released from the liquefied gas storage tank; and

Step S550: using a cold energy pipeline to deliver the cold energy generated by gasification to the arbitrary gas liquefaction equipment, so that the arbitrary gas liquefaction equipment obtains the cold energy to exchange the heat that is generated during a gas compression. Through the heat exchange, the gas in the arbitrary gas liquefaction equipment reaches or drops below a critical temperature for the liquefaction of the gas, so that the gas is liquefied, and the liquefied gas that is obtained by means of the liquefaction reaction enters the liquefied gas storage tank that is configured for the arbitrary gas liquefaction equipment.

It should be noted that the gas liquefaction equipment may be general gas liquefaction equipment, and the present invention is not limited to any specific structure of the gas liquefaction. For example, the gas liquefaction equipment may be separately provided with their own air cylinders, the air cylinders may share a common gas compressor, and may also be separately provided with respective gas compressors. When the gas liquefaction equipment liquefies the gas, the gas can be cooled, pressurized and liquefied according to its physical properties such as a liquefaction temperature, a liquefaction pressure and the like of the gas that enters the air cylinder. As for the first gas liquefaction equipment to liquefy the gas in terms of the order of levels, some dry ice may be added into the gas liquefaction equipment at an appropriate time to start the cooling process, and a pressure is applied in the gas liquefaction equipment when the temperature reaches or drops below the critical temperature for the liquefaction of the gas. For example, if in a level-by-level scheme of liquefaction the gas that is liquefied by the first gas liquefaction equipment is a carbon dioxide gas, the pressure can be applied in the gas liquefaction equipment when the temperature reaches or drops below the critical temperature of 31 degrees centigrade for the liquefaction, and the liquefied carbon dioxide enters the liquefied gas storage tank (part of the liquefied carbon dioxide may form dry ice).

Thus, according to the gas liquefaction method disclosed by the embodiment of the present disclosure, the liquefied gas that is obtained from the gas liquefaction equipment at a higher level by liquefaction can provide sufficient cold energy for the heat exchange of the gas liquefaction in the gas liquefaction equipment at a lower level, and therefore the cold energy provided by the liquefied gas that is obtained by the liquefaction at the higher level can be used level by level to liquefy the gas in a more convenient and energy-saving manner without having to continuously providing additional cold energy sources.

It can be understood that the cold energy that is generated by gasification may also be temporarily stored in a cold energy storage tank before being delivered to the gas liquefaction equipment through the cold energy pipeline 107. When any gas liquefaction equipment is in need of cold energy for liquefaction, the stored cold energy is then delivered to such gas liquefaction equipment.

In addition, according to the gas liquefaction method disclosed by the embodiment of the present disclosure, the gas liquefaction equipment may also be communicated with heat insulating pipelines. The heat insulating pipelines are used to collect heat energy that is generated during the liquefaction and deliver the heat energy to heat energy storage tanks for storage, so as to provide the heat energy when the gasification equipment exchanges heat of the liquefied gas. For example, the heat energy in the heat energy storage tanks may be delivered into the gasification equipment by a medium such as water, air and the like through the heat insulating pipelines, to reduce or avoid the additional provision of heat energy.

Sixth Embodiment

According to an implementation mode according to embodiments of the present invention, a gas liquefaction method can be applied in a wind field to solve the bottleneck problem in current technologies regarding a grid-connected wind power system. Specifically, for example:

For the liquefied gas storage tanks of the at least two pieces of gas liquefaction equipment, a gas outlet end of at least one liquefied gas storage tank is communicated with gasification equipment (for example, gas outlet ends of the liquefied gas storage tanks of the at least two pieces of gas liquefaction equipment are all communicated with the gasification equipment, or the gas outlet ends of the liquefied gas storage tanks of the gas liquefaction equipment that is not arranged at the foremost in terms of the levels are communicated with the gasification equipment); when a wind turbine in the wind field cannot supply sufficient electricity to a power grid, the liquefied gas in any liquefied gas storage tank communicated with the gasification equipment can be allowed to enter the gasification equipment for gasification; and an electric generator is driven by the gas released from the gasification equipment to supply electricity to the power grid.

Accordingly, with respect to the bottleneck problem on the grid connection caused by the instability of the wind energy or a failure of the wind turbine itself or the like, according to the embodiment of the present disclosure, an appropriate operation area for liquefying air can be selected in the wind field, and the gas liquefaction system according to the present embodiment is applied in the operation area to utilize excessive wind energy to liquefy air, gasify the liquefied gas when the wind energy is insufficient speed, stops, or if part or all of the wind turbines have failed, and release power to drive the electric generator to generate electricity so as to supply the electricity to the power grid. Therefore, the power supply of the power grid is extended, and the impact on the power grid due to large or fast fluctuation in the wind energy is reduced.

For example, the electric power that is generated by wind turbines in the wind field supplies an electric power source to the gas liquefaction system, which may be implemented in the following two manners: in the first, the wind turbines in the wind field generates electricity based on a predetermined power level, wherein the predetermined power level may be set according to the requirement of the power grid; when the wind energy is large and exceeds the predetermined power level, the wind energy which exceeds the predetermined power level may be centralized in the operation area and converted into the electric power as the electric power source of the gas liquefaction system; in the second, certain of the wind turbines may be selected in the wind field; when the wind energy is large, the selected wind turbines are used to provide the electric power source for the gas liquefaction system to liquefy air. Either of the above manners is acceptable. Furthermore, when the wind energy in the wind field is not continuous, intermittent wind energy may also be converted into electric energy and stored in a storage battery to supply the electric power source to the gas liquefaction system to start air liquefaction when the electric power in the storage battery is enough to start the gas liquefaction system.

It should be noted that according to the embodiment of the present disclosure, the gasification equipment may include one or more gasification equipment; for example, the gas outlet end of the liquefied gas storage tank of each gas liquefaction equipment may be communicated with one gasification equipment; for another example, the gas outlet of the liquefied gas storage tank of each gas liquefaction equipment may be communicated with respective corresponding gasification equipment separately, which is not limited in the present disclosure. According to the present embodiment, the gasification equipment may include necessary equipment such as a heat exchanger and the like.

When the wind turbines cannot supply sufficient electricity to the power grid, the decision as to which of the liquefied gas storage tanks is to be selected and how much liquefied gas to be released from the selected liquefied gas storage tank can be based on the requirements for stabilizing the power grid and extending the power generation under the actual circumstances, which is not limited in the present disclosure. Moreover, the released gas may also be delivered to the power grid together with the wind power of other wind turbines at the same time of driving the electric generator to supply power to the power grid, so as to eliminate the impact on the power grid due to the variation in the wind power of the wind turbines. For example, when the forecast indicates no wind, the gas in the liquefied gas storage tanks may be released to drive a motor to supply electricity to the power grid, so that the power grid can obtain the electric power source in time to ensure safe disconnection of the wind turbines from the grid before the wind turbines cannot supply power and disconnected from the grid, thereby minimizing the impact on the power grid. When the forecast indicates that the wind speed is high and the wind energy will exceed the predetermined power level, the gas driving equipment is started to drive the air to enter the gas delivery passageway to start the air liquefaction, and the excessive wind energy is converted into the liquefied gas for storage.

Seventh Embodiment

In combination with any of the above embodiments, when the gas is a gas mixture, such as natural air in a wind field, a gas liquefaction system according to the embodiment of the present invention can separate a gas mixture into several pure gases and liquefy the pure gases separately. Specifically, for example:

Filtration equipment may be provided for each gas liquefaction equipment respectively and used to separate the pure gases;

In an order of the levels from front to back, and starting from a gas inlet of a gas delivery passageway, at least two pieces of gas liquefaction equipment are communicated with the gas delivery passageway through the filtration equipment that is arranged for the gas liquefaction equipment one by one, wherein the gas inlet end of each gas liquefaction equipment is communicated with a separating opening of each filtration equipment that is arranged for the gas liquefaction equipment, and gas inlets of the respective filtration equipment are communicated with the gas delivery passageway;

As for the first gas liquefaction equipment that is communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway, the gas inlet of the filtration equipment of the first gas liquefaction equipment is communicated with the gas inlet end of the gas delivery passageway. As for arbitrary gas liquefaction equipment except for the first gas liquefaction equipment, the gas inlet of the filtration equipment of the arbitrary gas liquefaction equipment is communicated with a gas outlet of the filtration equipment of the previous gas liquefaction equipment that is arranged before the arbitrary gas liquefaction equipment through the gas delivery passageway;

The filtration equipment is used to filter the gas that enters the gas liquefaction system from the gas inlets of the filtration equipment; the separated pure gases enter the gas liquefaction equipment from separating openings; and the remaining gases are discharged out of the gas outlets.

For example, the gas may be the natural air in a wind field. The at least two pieces of gas liquefaction equipment may include carbon dioxide liquefaction equipment configured to liquefy carbon dioxide, oxygen liquefaction equipment configured to liquefy oxygen, and nitrogen liquefaction equipment configured to liquefy nitrogen, wherein the carbon dioxide liquefaction equipment is the first gas liquefaction equipment that is communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway, the oxygen liquefaction equipment is the second gas liquefaction equipment that is communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway, and the nitrogen liquefaction equipment is the third gas liquefaction equipment that is communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway.

In such an implementation, for example, a filtration membrane suitable to separate carbon dioxide may be included in the filtration equipment that is arranged at the gas inlet end of the carbon dioxide liquefaction equipment; a filtration membrane suitable to separate oxygen may be included in the filtration equipment arranged at the gas inlet end of the oxygen liquefaction equipment; and a filtration membrane suitable to separate nitrogen may be included in the filtration equipment arranged at the gas inlet end of the nitrogen liquefaction equipment.

For example, in terms of the order of levels, the carbon dioxide liquefaction equipment may be arranged at a higher level than that of the oxygen liquefaction equipment and the nitrogen liquefaction equipment, and the oxygen liquefaction equipment may be arranged at the same level as, or at a different level than the nitrogen liquefaction equipment; for example, the oxygen liquefaction equipment is arranged at a higher level than that of the nitrogen liquefaction equipment, so that oxygen is liquefied before nitrogen.

The gasification equipment is employed to perform heat exchange on liquefied carbon dioxide released from liquefied gas storage tank associated with the carbon dioxide liquefaction equipment to gasify the liquefied carbon dioxide when cold energy is needed for the liquefaction of the gas in the oxygen liquefaction equipment.

The cold energy that is generated during the gasification of the liquefied carbon dioxide is delivered to the oxygen liquefaction equipment through a cold energy pipeline, so that the oxygen liquefaction equipment obtains the cold energy to exchange heat that is generated during oxygen compression, and the oxygen in the oxygen liquefaction equipment can reach or drop below a critical temperature for the liquefaction of the oxygen in a quicker manner through the heat exchange, and therefore the oxygen is liquefied. The liquid oxygen that is obtained from the liquefaction reaction enters the liquefied gas storage tank that is configured for the oxygen liquefaction equipment.

When the cold energy generated during the gasification of the liquefied carbon dioxide released from the liquefied gas storage tank of the carbon dioxide liquefaction equipment is insufficient, the gasification equipment is used to perform the heat exchange on part of liquefied oxygen released from the liquefied gas storage tank that has obtained the liquefied oxygen to gasify part of liquefied oxygen;

The cold energy that is generated during the gasification of the liquefied oxygen is delivered to the oxygen liquefaction equipment and/or the nitrogen liquefaction equipment through the cold energy pipeline, so that the oxygen liquefaction equipment and/or the nitrogen liquefaction equipment obtain the cold energy to exchange heat generated during the gas compression, and the gas in the oxygen liquefaction equipment and/or the nitrogen liquefaction equipment can reach or drop below a critical temperature for the liquefaction of the gas in a quicker manner through the heat exchange, and therefore the gas in the oxygen liquefaction equipment and/or the nitrogen liquefaction equipment is liquefied.

Of course, the embodiments of the present disclosure are not limited to three pieces of gas liquefaction equipment only; more gas liquefaction equipment may be arranged. The embodiments are not limited to liquefying carbon dioxide, nitrogen and oxygen; for example, ammonia gas and the like may also be liquefied. The liquefied gas formed during the liquefaction may be pure liquefied gas or a mixture of liquefied gases, which is not limited in the present disclosure.

Eighth Embodiment

In combination with any of the above available embodiments, after liquefied gas is gasified to generate electricity and forms high-pressure gas, a part of the high-pressure gas may be naturally discharged in the surrounding space, and the remaining part of the gas may be recycled by gas recycling equipment, delivered back to gas liquefaction equipment through a gas recycling pipeline associated with the gas recycling equipment, and liquefied again to form a liquefied gas. For example, a gas outlet end of gasification equipment may also be communicated with a gas inlet end of the gas recycling equipment, and the gas recycling equipment can be used to recycle the gas discharged out of the gasification equipment. The recycled gas is delivered to gas inlet end(s) of one or more gas liquefaction equipment in the at least two pieces of gas liquefaction equipment through the gas recycling pipeline, so that the discharged gas returns to the gas liquefaction equipment again as much as possible for liquefaction.

For example, if each piece of gas liquefaction equipment is used to accommodate and liquefy different pure gases respectively, each liquefied gas storage tank may be correspondingly communicated with one individual gasification equipment. Correspondingly, the gas outlet end of each gasification equipment may be communicated with an independent gas recycling equipment, the gas outlet end of the gas recycling pipeline that is matched with the independent gas recycling equipment may be directly communicated with the corresponding gas liquefaction equipment that is used to accommodate and liquefy the same gas, so that the discharged pure gas may directly return to the gas liquefaction equipment for liquefaction, and therefore the wear and tear on filtration equipment is reduced,

A person skilled in the art would understand that the liquefied gas storage tanks may be closed containers that can be detached; the liquefied gas storage tanks in which the liquefied gas is stored can be sold as individual products. A storage warehouse provided with safety equipment may also be used to store the liquefied gas storage tanks.

It should be noted that the relational terms in the present disclosure, such as first, second and the like, are only employed to distinguish one entity or an operation from another entity or operation, and do not always claim or imply that there is any such actual relation or order between these entities or operations. Moreover, the term “comprise”, “include” or any other variants thereof intends to cover non-exclusive inclusions, so that a process, a method, an article or equipment including a series of elements not only includes the indicated elements but also includes other elements that are not listed explicitly or inherent elements for the process, method, article or equipment. In case of no further limitation, an element that is defined by the term “including a” does not exclude that additional identical elements also exist in the process, method, article or equipment including the element.

The above embodiments are exemplary embodiments of the present disclosure, and are not described to limit the protection scope of the present disclosure. Any modification, substitution, improvement and the like that is made within the spirit and scope of the present disclosure is included in the protection scope of the present disclosure. 

1. A gas liquefaction system, comprising: a gas delivery passageway, gas driving equipment and at least two pieces of gas liquefaction equipment that are arranged at different levels, wherein the gas driving equipment is arranged at a gas inlet end of the gas delivery passageway, the gas delivery passageway is communicated with gas inlet ends of the at least two pieces of gas liquefaction equipment, and each of the at least two pieces of gas liquefaction equipment is provided with a liquefied gas storage tank respectively; wherein the gas driving equipment is configured to drive a gas to enter the gas liquefaction system from the gas inlet end of the gas delivery passageway; wherein the at least two pieces of gas liquefaction equipment that are arranged at different levels are configured to liquefy the gas that enters the gas liquefaction system from a gas inlet end of the gas liquefaction equipment in an order of the levels, wherein the liquefied gas obtained by liquefaction enters liquefied gas storage tanks that are configured for the gas liquefaction equipment; and the gas liquefaction system further comprising: gasification equipment, configured to, when any arbitrary gas liquefaction equipment of the at least two pieces of gas liquefaction equipment is in need of cold energy for gas liquefaction, exchange heat with the liquefied gas released from a liquefied gas storage tank, the liquefied gas storage tank containing already liquefied gas and being associated with any gas liquefaction equipment which is at a level higher than or equal to the level of the arbitrary gas liquefaction equipment, thereby gasifying the liquefied gas released from the liquefied gas storage tank; and a cold energy pipeline, which is configured to deliver the cold energy generated by gasification to the arbitrary gas liquefaction equipment, so that the arbitrary gas liquefaction equipment receives the cold energy to exchange the heat generated during gas compression, such that the gas in the arbitrary gas liquefaction equipment reaches or drops below a critical temperature for the liquefaction of the gas through the heat exchange and is therefore liquefied, and the liquefied gas obtained by liquefaction enters the liquefied gas storage tank associated with the arbitrary gas liquefaction equipment.
 2. The gas liquefaction system according to claim 1, wherein: for the liquefied gas storage tanks associated with the at least two pieces of gas liquefaction equipment, a gas outlet end of at least one liquefied gas storage tank is communicated with the gasification equipment; and the gasification equipment is also configured to gasify the liquefied gas in any arbitrary liquefied gas storage tank that is communicated with the gasification equipment when a wind turbine in a wind field cannot supply sufficient electricity to a power grid; and the gas liquefaction system further comprising an electric generator configured to be driven by the gas released from the gasification equipment to supply electricity to the power grid.
 3. The gas liquefaction system according to claim 1, further comprising: heat insulating pipelines that are communicated with the gas liquefaction equipment and configured to collect heat energy generated during the liquefaction and deliver the heat energy to heat energy storage tanks for storage, so as to provide the heat energy when the gasification equipment performs heat exchange on the liquefied gas.
 4. The gas liquefaction system according to claim 1, further comprising: filtration equipment that is arranged for each piece of gas liquefaction equipment respectively and used to separate a gas mixture into pure gases; wherein, in an order of the levels from front to back, and starting from a gas inlet of the gas delivery passageway, at least two pieces of gas liquefaction equipment are communicated with the gas delivery passageway through the filtration equipment that is arranged for the gas liquefaction equipment one by one, wherein the gas inlet end of each gas liquefaction equipment is communicated with a separating opening of each filtration equipment that is arranged for the gas liquefaction equipment, and gas inlets of the respective filtration equipment are communicated with the gas delivery passageway; for the first gas liquefaction equipment that is communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway, the gas inlet of the filtration equipment of the first gas liquefaction equipment is communicated with the gas inlet end of the gas delivery passageway; and as for an arbitrary gas liquefaction equipment except for the first gas liquefaction equipment, the gas inlet of the filtration equipment of the arbitrary gas liquefaction equipment is communicated with a gas outlet of the filtration equipment of the previous gas liquefaction equipment that is arranged before the arbitrary gas liquefaction equipment through the gas delivery passageway; wherein the filtration equipment is configured to filter the gas that enters the gas liquefaction system from the gas inlets of the filtration equipment, the separated pure gases enter the gas liquefaction equipment from separating openings, and the remaining gases are discharged out of the gas outlets.
 5. The gas liquefaction system according to claim 4, wherein: the gas is natural air in a wind field; and the at least two pieces of gas liquefaction equipment comprise carbon dioxide liquefaction equipment configured to liquefy carbon dioxide, oxygen liquefaction equipment configured to liquefy oxygen and nitrogen liquefaction equipment configured to liquefy nitrogen, wherein the carbon dioxide liquefaction equipment is the first gas liquefaction equipment communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway, the oxygen liquefaction equipment is the second gas liquefaction equipment communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway, and the nitrogen liquefaction equipment is the third gas liquefaction equipment communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway.
 6. The gas liquefaction system according to claim 5, wherein: in terms of the order of levels, the carbon dioxide liquefaction equipment is arranged in front of the oxygen liquefaction equipment and the nitrogen liquefaction equipment, and the oxygen liquefaction equipment is arranged in front of the nitrogen liquefaction equipment; wherein the gasification equipment is configured to perform heat exchange on liquefied carbon dioxide released from the liquefied gas storage tank associated with the carbon dioxide liquefaction equipment to gasify the liquefied carbon dioxide when cold energy is needed for the liquefaction of the gas in the oxygen liquefaction equipment; wherein the cold energy pipeline is configured to deliver to the oxygen liquefaction equipment the cold energy that is generated during the gasification of the liquefied carbon dioxide, so that the oxygen liquefaction equipment receives the cold energy to exchange heat that is generated during oxygen compression, such that the oxygen in the oxygen liquefaction equipment reaches or drops below a critical temperature for the liquefaction of the oxygen and is therefore liquefied; and the liquid oxygen that is obtained from the liquefaction enters the liquefied gas storage tank associated with the oxygen liquefaction equipment; wherein the gasification equipment is also configured to exchange heat of the liquefied oxygen released from the liquefied gas storage tank that contains liquefied oxygen to gasify the liquefied oxygen when the cold energy generated during the gasification of the liquefied carbon dioxide released from the liquefied gas storage tank associated with the carbon dioxide liquefaction equipment is insufficient; and wherein the cold energy pipeline is also configured to deliver the cold energy that is generated during the gasification of the liquefied oxygen to the oxygen liquefaction equipment and/or the nitrogen liquefaction equipment, so that the oxygen liquefaction equipment and/or the nitrogen liquefaction equipment receive the cold energy to exchange heat generated during the gas compression, such that the gas in the oxygen liquefaction equipment and/or the nitrogen liquefaction equipment reach or drop below a critical temperature for the liquefaction of the gas, and is therefore liquefied.
 7. The gas liquefaction system according to claim 1, wherein: a gas outlet end of the gasification equipment is also communicated with a gas inlet end of gas recycling equipment, the gas recycling equipment is configured to recycle the gas that is discharged out of the gasification equipment, the recycled gas is delivered to gas inlet end(s) of one or more of the at least two pieces gas liquefaction equipment through a gas recycling pipeline, so that the discharged gas returns to the gas liquefaction equipment for liquefaction.
 8. A gas liquefaction method, applicable to a gas liquefaction system that comprises a gas delivery passageway, gas driving equipment and at least two pieces of gas liquefaction equipment that are arranged at different levels, comprising the steps of: arranging the gas driving equipment at a gas inlet end of the gas delivery passageway, communicating the gas delivery passageway with gas inlet ends of the at least two pieces of gas liquefaction equipment, and configuring a liquefied gas storage tank for each of the at least two pieces of gas liquefaction equipment respectively; using the gas driving equipment to drive a gas to enter the gas liquefaction system from the gas inlet end of the gas delivery passageway; using the at least two pieces of gas liquefaction equipment that are arranged at different levels to liquefy the gas that enters the gas liquefaction system from a gas inlet end of the gas liquefaction equipment in an order of the levels, wherein the liquefied gas obtained by liquefaction enters a designated liquefied gas storage tank associated with the gas liquefaction equipment; when any arbitrary gas liquefaction equipment of the at least two pieces of gas liquefaction equipment is in need of cold energy for gas liquefaction, using a gasification equipment to exchange heat with the liquefied gas released from the liquefied gas storage tank, the gas storage tank containing already liquefied gas and being associated with any gas liquefaction equipment which is at a level higher than or equal to the level of the gas liquefaction equipment in need of cold energy, thereby gasifying the liquefied gas released from the liquefied gas storage tank; and using a cold energy pipeline to deliver the cold energy generated by gasification to the arbitrary gas liquefaction equipment, so that the gas liquefaction equipment receives the cold energy to exchange heat generated during gas compression, such that the gas in the gas liquefaction equipment reaches or drops below a critical temperature for the liquefaction of the gas through the heat exchange, and is therefore liquefied, and the liquefied gas obtained by liquefaction enters the liquefied gas storage tank associated with the arbitrary gas liquefaction equipment.
 9. The gas liquefaction method according to claim 8, wherein: for the liquefied gas storage tanks associated with the at least two pieces of gas liquefaction equipment, a gas outlet end of at least one liquefied gas storage tank is communicated with the gasification equipment; and when a wind turbine in a wind field cannot supply sufficient electricity to a power grid, gasifying the liquefied gas in any arbitrary liquefied gas storage tank that is communicated with the gasification equipment; and using the gas that is released from the gasification equipment to supply electricity to the power grid.
 10. The gas liquefaction method according to claim 8, further comprising the steps of: communicating the gas liquefaction equipment with heat insulating pipelines; and using the heat insulating pipelines to collect heat energy that is generated during the liquefaction and deliver the heat energy to heat energy storage tanks for storage, so as to provide the heat energy when the gasification equipment performs heat exchange on the liquefied gas.
 11. The gas liquefaction method according to claim 8, further comprising the steps of: arranging a filtration equipment for each piece of gas liquefaction equipment respectively to separate a gas mixture into pure gases; communicating the at least two pieces of gas liquefaction equipment with the gas delivery passageway through the filtration equipment that is arranged for the gas liquefaction equipment one by one in an order of the levels from front to back and starting from a gas inlet of the gas delivery passageway, wherein the gas inlet end of each gas liquefaction equipment is communicated with a separating opening of each filtration equipment that is arranged for the gas liquefaction equipment, and gas inlets of the respective filtration equipment are communicated with the gas delivery passageway; for the first gas liquefaction equipment that is communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway, communicating the gas inlet of the filtration equipment of the first gas liquefaction equipment with the gas inlet end of the gas delivery passageway; and as for an arbitrary gas liquefaction equipment except for the first gas liquefaction equipment, communicating the gas inlet of the filtration equipment of the arbitrary gas liquefaction equipment with a gas outlet of the filtration equipment of the previous gas liquefaction equipment that is arranged before the arbitrary gas liquefaction equipment through the gas delivery passageway; and employing the filtration equipment to filter the gas that enters the gas liquefaction system from the gas inlets of the filtration equipment, wherein the separated pure gases enter the gas liquefaction equipment from separating openings, and the remaining gases are discharged out of the gas outlets.
 12. The gas liquefaction method according to claim 11, wherein: the gas is natural air in a wind field; and the at least two pieces of gas liquefaction equipment comprise carbon dioxide liquefaction equipment configured to liquefy carbon dioxide, oxygen liquefaction equipment configured to liquefy oxygen and nitrogen liquefaction equipment configured to liquefy nitrogen, wherein the carbon dioxide liquefaction equipment is the first gas liquefaction equipment that is communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway, the oxygen liquefaction equipment is the second gas liquefaction equipment that is communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway, and the nitrogen liquefaction equipment is the third gas liquefaction equipment that is communicated with the gas delivery passageway starting from the gas inlet end of the gas delivery passageway.
 13. The gas liquefaction method according to claim 12, wherein: in terms of the order of the levels, the carbon dioxide liquefaction equipment is arranged in front of the oxygen liquefaction equipment and the nitrogen liquefaction equipment, and the oxygen liquefaction equipment is arranged in front of the nitrogen liquefaction equipment; wherein the gasification equipment is configured to perform heat exchange on liquefied carbon dioxide released from the liquefied gas storage tank associated with the carbon dioxide liquefaction equipment to gasify the liquefied carbon dioxide when cold energy is required for the liquefaction reaction of the gas in the oxygen liquefaction equipment; wherein the cold energy pipeline is configured to deliver to the oxygen liquefaction equipment the cold energy that is generated during the gasification of the liquefied carbon dioxide, so that the oxygen liquefaction equipment receives the cold energy to exchange heat that is generated during oxygen compression, such that the oxygen in the oxygen liquefaction equipment reaches or drops below a critical temperature for the liquefaction of the oxygen, and therefore the oxygen is liquefied; and the liquid oxygen that is obtained from the liquefaction reaction enters the liquefied gas storage tank that is configured for the oxygen liquefaction equipment; wherein the gasification equipment is also configured to exchange heat of the liquefied oxygen released from the liquefied gas storage tank containing liquefied oxygen to gasify the liquefied oxygen when the cold energy that is generated during the gasification of the liquefied carbon dioxide released from the liquefied gas storage tank of the carbon dioxide liquefaction equipment is insufficient; and wherein the cold energy pipeline is also configured to deliver the cold energy that is generated during the gasification of the liquefied oxygen to the oxygen liquefaction equipment and/or the nitrogen liquefaction equipment, so that the oxygen liquefaction equipment and/or the nitrogen liquefaction equipment obtain(s) the cold energy to exchange heat that is generated during the gas compression, such that the gas in the oxygen liquefaction equipment and/or the nitrogen liquefaction equipment reaches or drops below a critical temperature for the liquefaction of the gas, and is therefore liquefied.
 14. The gas liquefaction method according to claim 8, wherein: a gas outlet end of the gasification equipment is also communicated with a gas inlet end of gas recycling equipment; and the gas recycling equipment is configured to recycle the gas that is discharged out of the gasification equipment, the recycled gas is delivered to gas inlet end(s) of one or more of the at least two pieces of gas liquefaction equipment through a gas recycling pipeline, so that the discharged gas returns to the gas liquefaction equipment for liquefaction. 